During cervical spinal surgery for the fusion of an intervertebral disc, an anterior approach, discectomy and insertion of a spacer/cage are often performed. However, in these situations, the spine surgeon often prefers not to insert a plate on the anterior surface of the disc space with fixation through the anterior face of the cephalaud and caudal vertebral bodies. This reluctance stems from the observation that the anterior plate can be situated too proud and so its profile can sometimes cause patient discomfort and cause dysphasia and/or dysphonia.
In some fusion cases using a stand alone spacer, the surgeon must insert a fixation device (such as a screw) into the spacer at a sharp angle through sometimes challenging approaches. This can be especially difficult for the cervical spine, as the surgeon needs to either deliver the screw down into the inferior vertebral body but may be obstructed by the patient's chin, or deliver the screw up into the superior vertebral body but may be obstructed by the patient's sternum.
U.S. Pat. No. 7,135,043 (Nakahara) discloses an intervertebral cage comprising regulated insertion direction ridges. The cage may include a main body defined by an upper surface, a lower surface, and a pair of side surfaces. A withdrawal prevention portion is provided on the upper and/or the lower surfaces of the main body and asymmetrically with respect to the side surfaces in a top or bottom plan view. The withdrawal prevention portion regulates an insertion direction of the intervertebral cage. The portion of the Nakahara device that holds the screws does not possess teeth upon its upper and lower surfaces.
U.S. Patent Publication No. 2007-0250167 (“Bray”) discloses a device for the fixation and support of bone bodies includes a base member for implantation into a patient at a location between two bone bodies. The base member of the device includes an enclosed chamber for receiving fusion material and apertures for receiving bone fasteners that can be embedded into the adjacent bone bodies. The device further includes protrusions extending from the base member, wherein the protrusions are configured for engagement with one or more bone bodies upon implantation and for progressive penetration into at least one bone body over a period of time subsequent to the implantation. However, the faceplate that holds the screws is not designed to be implanted in the disc space, but rather cloaks the anterior wall of the upper vertebral body.
The Globus Coalition Cage has protrusions that begin from the anterior face, and upon insertion, displace bone from the anterior face through the desired depth in a track formation rather than penetrating from within the space.
U.S. Pat. No. 7,232,464 (Mathieu) discloses an intervertebral implant in the form of a three-dimensional structure comprising (a) a top side and an underside that are designed to rest against the end plates of two adjacent vertebras, (b) a left side face and a right side face, (c) a front face and a rear face, (d) a horizontal center plane situated between the top side and the underside, (e) a vertical center plane situated between the left side face and the right side face and (f) a plurality of boreholes passing through the implant structure that are designed to receive longitudinal affixation elements, the axes of said elements intersecting the horizontal center plane. At least one of the boreholes is designed in a manner that the affixation element received in it can be rigidly connected to the intervertebral implant. The connection is implemented using a thread or by matching conical surfaces.
U.S. Patent Publication No. 2008-0306596 (“Jones”) discloses a method and apparatus for use in spinal fusion procedures. An interbody fusion device has a first piece that is a load bearing device designed to bear the axial loading from the end plates of adjacent vertebrae. A second piece of the interbody fusion device is a retention device whose function is to prevent migration of the load bearing device. One or more fasteners secure the retention device to the vertebrae above and below the load bearing device. The fasteners cause the end plates of the vertebrae to compress the end plates to the load bearing device to facilitate proper fusion.
U.S. Patent Publication No. 2008-0249625 (Waugh) discloses a composite interbody spacer includes a first portion (such as a faceplate) formed of a first material and a second portion (such as a cage) formed of a second material.
U.S. Patent Publication No. 2008-0249575 (“Waugh”) discloses a stand alone fusion cage in which the apertures that receive the bone anchors have an integral locking ring formed therein.
PCT Published Patent Application WO 02/13732 (“Bramlet”) discloses an apparatus and method for fusing opposing spinal vertebrae. In an embodiment for a spinal implant of the present invention, the implant includes a body assembly and a retention member coupled to the body assembly. The retention member includes a tang where the tang is extendible from the body assembly. In a method of the present invention, the method includes the step of inserting an implant between adjacent vertebrae with a retention member of the implant in a first retracted configuration. The method also includes the step of configuring the retention member in a second extended configuration wherein the retention member is in its second extended configuration, a portion of a tang of the retention member extends from the implant and into one of the adjacent vertebrae.
U.S. Pat. No. 6,336,928 (“DePuy France”) discloses a device for joining at least two vertebral bodies, which comprises at least one plate equipped at each end with anchoring parts which can be introduced substantially vertically into seats previously established in the vertebral bodies to be joined, and then, after introduction, can be folded back at an angle towards one another in order to exert a constant compression of the vertebral bodies and to ensure perfect anchoring, wherein each anchoring part is connected to the ends of the corresponding plate via a central connection zone delimiting two profiled notches in order to permit deformation of the zone, in such a way that each pair of anchoring parts permits a compression, both at the level of the plate and at the level of its ends, and in such a way that the anchoring parts at each end of the plate permit a clamping which prevents any extraction.
U.S. Pat. No. 6,773,437 (“Ogilvie”) discloses a fusionless method of correcting spinal deformities in growing adolescents is disclosed utilizing a shape memory alloy staple. Various embodiments of the shape memory alloy staple include features such as barbs on the inner and outer surfaces of the prongs in the shape memory alloy staple as well as the use of notches on the crossbar or cross plate connecting the prongs to the shape memory alloy staple. In some embodiments, the shape memory alloy staple has an aperture defined through the cross plate for receiving a bone screw or other bone anchor which in turn allows the interconnection of a longitudinal member.
U.S. Pat. No. 7,594,931 (“LDR I”) discloses an intervertebral arthrodesis for insertion in an intervertebral space separating opposite faces of two adjacent vertebrae has a ring shaped intervertebral cage having a bar that extends perpendicular to the axis of the spine. The bar has a height less than the rest of the cage. A surface of the cage contacting the vertebrae has an undulating shape for limiting sliding of the cage in a plane parallel to the vertebrae faces.
PCT Published Patent Application WO 2008/149223 (“LDR II”) discloses an intersomatic cage, an intervertebral prosthesis, an anchoring device and an instrument for implantation of the cage or the prosthesis and the anchoring device, as well as a system and a method for implanting spinal implants and anchoring devices in vertebrae. An intersomatic cage or an intervertebral prosthesis fit closely to the anchoring device, which includes a body of elongated shape on a longitudinal axis, of curved shape describing, along the longitudinal axis, an arc whose dimensions and radius of curvature are designed in such a manner that the anchoring device may be implanted in the vertebral plate of a vertebra by presenting its longitudinal axis substantially along the plane of the intervertebral space, where the anchoring device is inserted, by means of the instrument, through a slot located in at least one peripheral wall of the cage or on at least one plate of the intervertebral disc prosthesis to penetrate into at least one vertebral plate
PCT Published Patent Application WO-2010/028045 (“Lawton”) discloses an intervertebral implant for insertion into an intervertebral disc space between adjacent vertebral bodies or between two bone portions. The implant includes a spacer portion, a plate portion operatively coupled to the spacer portion and one or more blades for securing the implant to the adjacent vertebral bodies. The blades preferably include superior and inferior cylindrical pins for engaging the adjacent vertebral bodies. The implant may be configured to be inserted via a direct lateral transposals approach. Alternatively, the implant may be configured for insertion via an anterior approach.
U.S. Published Patent Application 2005-0149192 (“Zucherman I”) discloses an intervertebral implant has a fusion body with at least one keel that anchors the implant into cancellous bone of at least one vertebral body. A method for implantation includes lateral implantation of the implant.
U.S. Published Patent Application 2005-0149193 (“Zucherman II”) discloses an intervertebral implant has a fusion body with at least one keel that anchors the implant into cancellous bone of at least one vertebral body. A method for implantation includes lateral implantation of the implant.
U.S. Published Patent Application 2004-0260286 (“Ferree”) discloses an intradiscal components associated with Total Disc Replacements (TDRs), for example, are maintained in a disc space with keels having attributes that resist extrusion, pull-out, and/or backout. In the preferred embodiment, the keel is curved to resist extrusion, particularly anterior or posterior extrusion. The invention may include a TDR with a pair of endplates, each with a keel extending into a different vertebral body, and wherein the keels are angled or curved in different directions to resist extrusion. In alternative embodiments, the keel may include one or more members that extend outwardly to resist extrusion. Such members may be spring-biased, composed of a shape-memory material, or extend outwardly in response to an applied mechanical force, as might be applied by turning a screw. The keel may further include a bone-ingrowth plug or coating or ‘teeth’ to resist extrusion. Keels according to the invention may also be configured to resist extrusion through the addition of an elongate member that penetrates a vertebral body and the keel. Such a member may be a secondary keel or screw.
U.S. Published Patent Application 2008-0167666 (“Fiere”) discloses equipment including at least one U-shaped clip whose lateral branches have sections and widths such that they may be inserted in the vertebral bodies of two vertebrae by impaction on the intermediate branch of the clip, so as to rest along the cortical bones of the vertebral bodies, and whose intermediate branch is deformable in such a way as to allow a reduction of the distance between the lateral branches; the intermediate branch, before implantation, has a length such that one of the lateral branches may be positioned slightly above the cortical bone forming the plate of the subjacent vertebra while the other lateral branch may be positioned slightly below the cortical bone forming the plate of the subjacent vertebra, and has, after deformation, a length such that the two lateral branches may be brought closer to each other.
U.S. Published Patent Application 2010-0004747 (“Lin”) discloses a trans-vertebral and intra-vertebral plate and a rectangular cage with a slot for the plate of spinal fixation device are for neutralizing intervertebral movement for the spinal interbody fusion. The rectangular cage with a vertical or oblique slot is inserted into the intervertebral space from the lateral or anterior side of the spinal column and then the plate is inserted through the slot of the cage and hammered into and buried inside two adjacent vertebral bodies, to achieve three-dimensional intervertebral fixation.
The cited art does not disclose a fusion device that accommodates anti-migration fixation elements adjacent to the device, wherein the anti-migration fixation elements are then secured to the fusion device with another component.
The prior art does not disclose a zero-profile cage with anti migration elements secured into bone approximately adjacent to a surface of the cage within disc space, wherein the anti-migration fixation elements have the ability to provide compression onto the graft area upon addition of another component to the construct.
WO2009-064644 (Synthes) discloses a low profile intervertebral implant for implantation in an intervertebral disc space in-between adjacent vertebral bodies. The intervertebral implant includes a plate preferably coupled to a spacer. The plate is preferably formed from a first material and the spacer is preferably formed from a second material, the first material being different from the second material. The plate is preferably sized and configured so that the plate does not extend beyond the perimeter of the spacer. In this manner, the plate preferably does not increase the height profile of the spacer and the plate may be implanted within the intervertebral disc space in conjunction with the spacer.